LIGHT EMITTING ELEMENT DRIVING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a drive circuit of a three-terminal light emitting element wherein speed is high, quenching characteristic is high, and application to high speed optical transmission is enabled. SOLUTION: Driving of the three-terminal light emitting element of high speed and high quenching characteristic is realized with a light emitting element driving circuit 3 provided with a modulation part 4 and a control part 5. The modulation part 4 performs intensity modulation of the three-terminal light emitting element 1 by changing the amount of current to an emitter terminal according to an input signal 2 to the element 1, in the common base three- terminal light emitting element 1. The control circuit 5 performs gate switching control of the intensity modulated light of the element by changing a voltage applied to a collector terminal according to the input signal 2.